The subject matter of this disclosure relates to improved frozen product dispenser systems and methods wherein a product is placed into a cooled hopper and the product is then fed from the hopper into a freezing and dispensing chamber where it is frozen and dispensed. More specifically, the subject matter of this disclosure is related to improved systems and methods of controlling the refrigeration and freezing of product of a frozen product dispenser.
Frozen product dispensers, generally, have been known in the art and have been used to freeze and dispense a variety of products including, but not limited to food products such as beverages, ice cream, yogurt, and other food items. Such prior art dispensers have suffered from various shortcomings and/or limitations.
The temperature and viscosity of the ingredients within the mixing chamber may be maintained by a control system that controls the refrigeration system. A method for controlling a frozen beverage machine's barrel refreeze cycle is based on the beater motor's torque (or power consumption). When the measured torque on the beater motor drops below a specified threshold, the machine initiates a freeze cycle and chills the barrel until the torque on the motor reaches a higher specified torque. While this is an indicator of the quality of the frozen product, other sensors throughout the dispensing device may be used to ensure that all of the functions work properly and that the motor torque reading is not providing an erroneous value.
In normal operation, a mix of ingredients are poured into a hopper, and some portion of that mix is allowed to flow downward into the freezing chamber. A motor outside of the freezing chamber drives a beater, which mixes the mix with air. Simultaneously a refrigeration unit chills the mix in the freezing barrel rapidly cooling it to the desired temperature.
Over time, the freezing barrel will lose heat through entropy and the freezing cycle will need to be repeated. Also, product will be dispensed and new mix added which will be at a temperature higher than the product in the freezing chamber. Since the goal of a frozen food dispenser is to provide uniform and quality product, the freezing cycle must be carefully regulated to ensure that the product does not deviate too far from optimal conditions.
To address this goal of providing consistent and quality product, several processes are loaded into the controller of the dispensing unit, and in fact, multiple controllers may be designed into the unit to guard against the failure of the primary controller. The controller may be a PID (proportional-integral-derivative) controller, a microprocessor, or similar electronic control apparatus. The main control process will bring the mix to a desired product using all sensors available to it under normal circumstances. While the units are built with the highest achievable quality standards, components such as sensors are known to fail, or to be jarred loose from their designed positions resulting in erroneous readings being fed into the control processor. Since relying upon those erroneous readings may provide undesirable product, the readings received by the control processor are checked against expected norms. If a sensor is providing readings that are outside of expected norms, the controller may distrust the reading and implement an alternate control program in an attempt to continue to provide desirable product. In creating the programming for the controllers, two objectives come to the forefront: (i) ensure that the tolerances around the expected sensor readings are not too wide to accept skewed readings but yet not too tight to reject correct readings and (ii) implement alternative control programs that will continue to provide quality product ready for dispensing even under rather adverse conditions resulting from the loss of inputs and feedbacks.
Under adverse conditions, the logic that will be used in exemplary dispensing systems must rely upon input and feedback from components that normally do not provide the primary inputs for the process. As such, the logic must be flexible and anticipate conditions that may prevent it from providing a quality food product.
One of several objects of the teachings of this disclosure is to resolve or reduce the identified—and other—shortcomings and/or limitations in prior art frozen product dispensers.